Method of molding



April 13, 1937. H. B. MYERS 2,076,790

METHOD OF' MOLDING Filed July 1, 1955 ATTORNEYS Patented Apr. 13, 1937PATENT OFFICE METHOD OF MOLDING Henry B. Myers, Cleveland Heights, Ohio,assignor to The Ferro Machine & Foundry Company, Cleveland, Ohio, acorporation of Ohio Application July 1, 1935, Serial No. 29,231

1 Claim.

This invention relates to the art of molding, and more p-articularly toa novel method and apparatus for forming sand molds for the productionof cast metal articles.

More specifically, this invention has to do with a novel method andapparatus for forming green sand molds, having one or more undercutrecesses or grooves in a Wall thereof, for the production of cast metalarticles having one or more corresponding projections thereon such asbrake drums having annula'rly extending ridges or iins. Heretofore castmetal brake drums of this form have been provided with the desiredridges or fins by machining grooves in an annular surface of the l5 drumto leave such ribs or fins upstanding. Such machining of the cast metallbrake drums has involved considerable additional expense. By my novelmethod and apparatus, as will be explained more fully hereinafter, thesand mold is formed with one or more undercut recesses or grooves in awall thereof whereby the desired ridges or ns are cast integral on thesurface of the brake drum.

It is therefore an object of the present invention to provide a novelmethod of molding wherein the cavity of a green sand mold is extended byforming an undercut recess in a wall thereof.

Another object of the invention is to provide a novel method of moldinginvolving the forming of a green sand mold with a cavity therein havingsubstantially the shape of the body of the casting desired, and formingone or more undercut recesses or grooves in-a wall of the cavity toprovide the same with extensions corresponding with projections or nsdesired on the casting.

Still another object of this invention is to provide a novel method ofmolding wherein the forming of the undercut grooves or recesses isaccomplished by rolling.

A further object of this invention is to provide novel molding apparatusembodying a ridged roller and means for causing relative traversingmovement between the roller and a wall of the cavity of a sand mold.

Still another object of this invention is to provide novel moldingapparatus, of the type referred to, embodying means for eccentricallymounting the ridged roller.

Other objects and advantages of the invention will be apparent from thefollowing description when taken in conjunction with the accompanyingsheet of drawings, wherein Fig. l is a top plan View of moldingapparatus embodying my invention.

Fig. 2 is a transverse sectional view thereof taken on line 2-2 ofFig. 1. c

Fig. 3 is a partial transverse sectional view showing the shape of themold cavity prior to the forming of the vgrooves or recesses in the wallthereof, and

Fig. 4 is a partial transverse sectional view taken through a ribbedbrake drum produced by a mold formed according to my invention.

More detailed reference will now be made to the accompanying drawing forthe purposeA of describing my novel method and apparatus for makingvsand molds. It will be understood, of course, that the apparatus shownin the drawing is to be regarded as illustrative only and that it issubject to variation within the scope of .the appended claim.

In accordance with my novel method, as will be explained more in detailhereinafter, I form a green sand mold with a cavity thereincorresponding in shape substantially with the body of the metal articleto be cast, and then form one or more recesses, for example grooves orthe like, in a side wall of the recess to correspond with projections orfins desired on the article. the recesses or grooves may be formed inthe wall of the mold cavity in various ways, my invention contemplatesthe forming of these grooves by a rolling operation whereby the groovesare formed by pressing the ridges of a ridged roller into the sand ofthe mold as relative traversing movement takes place between the rollerand the mold.

In Figs. 1 and 2 of the drawing I show novel apparatus for carrying outmy method, although it should be understood that the method can bepracticed with the' aid of various other kinds of apparatus ormachinery. As shown in the drawing, my novel apparatus includes asupport I0 which is preferably in the form of a metal plate adapted torest upon the mold box or section II containing the green sand I2 inwhich the mold cavity I3 is formed. The plate support III may beprovided with laterally extending ears I4 corresponding with the ears I4of the mold section II and having openings I5 in which the dowel pins I6engage. A roller I8 projects from the underside of the plate support I0and is adapted to extend into the cavity or recess I3 of the mold whenthe support rests upon the section I I in the position shown in Fig. 2of the drawing.

The roller I8 may be formed of metal, or any other suitable material,and has on its outer periphery a plurality of angularly extending ridgesor fins 20 corresponding in number, size and cross sectional shape withthe ridges or fms desired..

Although' on the cast metal articles to be produced. The ridges or finsmay be formed on the roller by machining grooves 2li in the facethereof. The roller I8 cooperates with the side wall 22 of the moldcavity to form a plurality of undercut grooves or recesses 23 in thecavity wall. I find that best results are obtained when the roller I8 isof relatively large diametenand although the size of the roller may bevaried somewhat, it may have a diameter as' great, or greater than, thesemi-diameter of the mold cavity in which the roller is to operate. Y

For operatively mounting the roller I8 on the plate support I0, Iprovide the latter with a swinging arm 25 which carries the roller. Thearm 25 may be mounted for swinging or rotary movementV relative to theplate support I0 by providing the arm with a shaftor spindle V26 whichis rotatable in and extends through a.V

bearing 21 provided on the support. The free end of the arm 25 isprovided with aboss or enlargement 28 in which a spindle 29 is rotatablymounted. This spindle projects outwardly from opposite sides of the bossV28 and the projecting be interposed between the eccentric portion 30 AVand the roller I8. Y

Y VThe gear 32 of the spindle 29 meshes with a vrelatively stationarygear 36 whichzis connected to the plate support I0 by means of screws31. The gear 36 has an opening therethrough aligned 40 with the bearingopening 2'I so asto accommodate Ythe shaft 26; The Shaft 26 jmaybelprevented 'frorn'dropping downwardly in the.l bearingj21 by means of acollar 38, which is secured to the shaft above the plate support I0 andserves as a thrust bearing. A "hollow cover 39-'may be secured Yto theplate support IU aroundthe thrust bearingv collar 38 to protect the sameand to excludesand and other foreign matterrtherefrorn. i

The shaft 26 may be rotatedby any suitable power means, for example bymeans of the hand lever or crank 40 connected to theU outer end thereofit Y i From the arrangementgjust described it will be seen that when thecrank 40 is rotatedV the shaft 26 will cause the arm 25 to sweep aroundbeneath the plate support I0 and causefthe spindle 29 to revolve aroundthe xed gear 36. Since Vthe gear 32 of the spindle meshes with the fixedgear 36 it will be seen that such revolving of the Vspindle Vwill causethe spindle to rotate in the boss 28 of the arm 25. rI'he revolvingoffthearm 25 causes the roller I8 to be moved around the wallof the moldcavity, and thefrotation of the 1spindle29 and its eccentric portion 30causes the roller to be alternately pressed against and moved away fromthe face of the side wall of the mold cavity. The alternate moving ofthe roller against and yaway from the side wall of the mold cavity bythe eccentric portion 30 as the roller is swung around within the cavitycauses the ridges 20 of the roller to press or cut into the sand of themold with a sweepingf'or slicking action to form the grooves orYrecesses 23'therein.

The gears 32 and 36 are Yso designed that the relatively fixed gear 36is of larger pitch dialneter and has a greater number of teeth than thegear 32. Because of the larger number of teeth of the xed gear 36 therevolving of the arm 25 will cause the spindle 29 to rotate somewhatmore than two turns during one revolution of the arm 25.' Hence byrevolving the crank 40 a suflicient number of times the roller I8 willbe pressed against the entire perimeter of the side wall of the moldcavity and will form continuous grooves 23 of the desiredcrosstsectional shape and depth therein.

In Fig. 4 of Vthe drawing I have shown, by way of example, a crosssection through the rim part of a cast metal brake drum 4I havingaYgenerally cylindrical body portion 4I withv annular ridges or fins 4Ithereon. In carrying out my novel methodof making sand molds forproducing the brake drums 4I or likeA articles, a mold cavity is firstformed. in the mold section II by packing the sandl I2 around a patternwhich corresponds` in shape with the cylindrical body portion of the`metal article to be producedY The withdrawing of the pattern from thepacked sand` Il and the roller will enter the mold cavity' I3 withoutscraping'against the side wall thereof.'`

After the plate support has been `thus applied to pins I6 engaging inthe openings I5, the Vcrank 40 is revolved to cause the rolle!I8'totraverse the side wall 22 ofthe mold cavity and form. the grooves23 therein in the manner explained above. After the grooves have beenrolled into the wall of the mold cavity the eccentric portion 30 isagain brought to a position from that shown in the mold section I I andpositioned thereon by the Fig. 2 to disengage the ridges 20 ofthevroller from the grooves which have been formed in the cavitywall.The plate support I0 can thenl be lifted from the mold section and theroller I8 therebywithdrawn from the mold cavity without damaging thegrooves which have been yformed inV the cavity wall. n t

To facilitate the use ofthe apparatus it may be desirable to provideindicating means for visibly indicatingvto ythe operator the position ofthe-ec'-V i centric portion 30 of the spindle 29. For this purpose I mayprovide on the shaft 26 a gearr42 of the same pitch diameter as therelativelyfixed gear 36. 'I'he gear 42 drives a gear 43 which is of thesame pitch diameter as the gear 372. The gear 43 carries an indication,such as a mark or projecting pin 44, which is located on the gear tocorrespond with the angular position of the offset portion of theeccentric 30. A fixed 'reference mark, such as a pointerr45, may belocatedadjacent the gear 43. I'he gear 43 and the pointer 45 may beconveniently mountedV upon a. lug or projection 46 extending above theplate support I0.

When the pin 44 registers with the pointer 45 the Y the Wall of the moldcavity. When the pin 44 f moves to a position diametrically opposite thepointer the operator knows that the roller has been disengaged from thecavity wall and canbe Withdrawn from the mold Without damage thereto.

To protect and support the upper edge of the mold cavity during therolling operation I may provide the plate support Ill with a ring 48 onthe underside thereof which has a contact face for engagement with thesand, corresponding in shape with the contour already given to the sandby the pattern around Which the sand Was packed. Similarly, the bottomWall of the mold cavity may be protected during the rolling operation bya removable plate 49 applied thereto. As shown in Fig. 2, the roller I8is in close running cooperation with the ring 48 and the plate 49.

l5 If desired, the plate support I0 may be provided with one or morethreaded openings 50 to receive lifting devices, such as screw-eyes, tofacilitate the handling of the apparatus and the application of the sameto the mold sections I I.

20 From the foregoing description and the accompanying drawing it willnow be readily seen that I have provided a novel method of forming greensand molds for the production of cast metal articles having projectionsthereon such as brake 25 drums having annular ridges or fins. It will beunderstood further that by my novel method undercut recesses or groovescorresponding With the projections or ridges of the article are formedin a side wall of the mold cavity by a rolling operation Whereby theridges of a ridged roll are pressed into the sand. It Will also bereadily understood that I have provided novel apparatus for formingundercut recesses or grooves in a Wall of green sand molds wherebyarticles having pro-v jections or fins thereon can be produced moreeconomically than has been possible heretofore by machining the casting.

While I have disclosed the novel method and apparatus of my invention ina somewhat detailed manner, it will be understood, of course, that I donot Wish to be limited to the precise steps of procedure and details ofconstruction herein described, but regard my invention as including suchchanges and modifications as do not constitute a departure from thespirit of the invention and the scope of the appended claim.

Having thus described my invention, I claim:

'Ihe method of molding which comprises forming a green sand mold havinga substantially cylindrical recess therein, and then swinging a ridgedroller around in the recess and alternately moving the roller againstand away from the Wall of the recess during such swinging and therebycausing the ridges of the roller to be pressed into the Wall with agyratory slicking action.

HENRY B. MYERS.

